A recent discussion here on Smilodon’s Retreat has prompted me to explain (again) that mutations, while not the only method of altering genetic codes, are still capable of creating diversity in living things.
The claim is that mutation alone cannot account for the diversity of life. Since the commenter specifically mentioned that he/she is OK with evolution, the question really is asking… where does the diversity of life come from.
One the one hand, we have the evolutionary explanation. That is, all the taxonomic diversity we think we see is really a hold-over from trying to fit ancient organisms into a classification system based on modern organisms. The secret to diversity is that, really, speciation is the only thing that needs to happen. Every taxonomic group above species (depending on what definition of species you use) is really just a convenient approximation for us humans to group things.
If this explanation is correct, then the ID proponents that admit evolution can cause speciation have lost the bigger game. This is because speciation is the only thing that exists. Speciation over time will result in greater and greater differences between species (especially as some species that were transitional will have gone extinct), the appearance of which is that of the “sudden appearance” of large taxonomic groups in the history of life.
An example that might help (and one I’ve used before) is that of families. You and your brother are different, but very closely related. The children of you and your brother are also fairly closely related, sharing roughly 1/4 of the same genes. They are cousins though. These kids will grow up and have their own families. Now the youngest group are second cousins and while, more closely related to each other than to the majority of the rest of the human population, they are getting more and more distinct. Another generation and the children might not even realize that they are related even if they go to the same school or live in the same town. Two more generations and you’ve got what are essentially separate family groupings that have never met, even though they are only five generations removed from a common ancestor (your parents).
The families, by this point, may be radically different. Some living in rural towns, some in urban cities. Some are religious, some are not. Some are highly educated, some are not. Some are Smith’s, some are Richardson’s, some are McAnder’s, and some are Washington’s. I could go on. The point is that nothing has occurred here except time and the normal mating practice of humans.
On the other hand, we have the intelligent design explanation. Which, as far as I’ve been able to tell (because literally no one will answer my question on the subject) is “Some intelligent thing, did something, at some point in time, using an unknown (and possibly unknowable) process. The exact nature of this intelligent thing is, by all accounts, totally immaterial to the nature of what it did and besides which, we are specifically barred from investigating the intelligent thing anyway.”
Which brings me to the paper I’d like to talk about today. My friend Wesley Elsberry (and some others) did some recent work with Avida and developed some modules for the software that allows Avida organisms to move. While this doesn’t sound particularly interesting, it is.
What Wesley did was create a “playing field” for the organisms. Then he put a pile of resources in a spot on the board. The resources created a gradient that was highest at that point.
Then they put some Avida organisms on the board and let them move… and evolve. Mutation was the only mechanism of change in the population. There wasn’t any sex or other exchange of genetic information. The initial batch of organisms just randomly moved through the field. The movement cost them though. The organisms need the resources. Moving costs them resources that they need to reproduce.
In the end, even with only mutation as the mechanism of evolution, the organisms evolved eight unique behaviors used to get them the resources that they needed. The organisms also went from randomly distributed around the board (only covering 2% of the board) to the majority of the organisms tightly clustered in the high resource area. One of the evolved types could also follow the resource peak if the researchers moved it.
In other words, mutation alone was perfectly adequate to generate a variety of unique organisms and allow them to flourish. Even more, there was a diversity of organism types. Though there was but a single resource, clustered in a single area, eight types of organisms evolved, each with a different method for finding the most resource.
Every evolutionary run produced at least one recognizable movement strategy. Because each run began with an Avidian whose only capability was self-replication, initially what movement occurred showed no such recognizable movement strategy. Almost all runs resulted in the successive evolutionof two or more movement strategies (e.g., Figure 7)
Now, this quote from the paper also illustrates a common complain from creationists about the use of software to emmulate evolution. That is, the programmers inserted the needed code somehow so that it would act like evolution, but really it was designed.
As this shows, that’s not the case. In every run of this simulation, the only thing the initial organisms could do was self-replication. Those organisms that had mutations that allowed them to move became successful. That’s how evolution works. In the land of the eyeless, even the light-sensitive cell is king.
If the code for search strategies was somehow inserted into the code, then it should be trivial for someone to request a copy of the software, examine it, and find examples of the code that causes the organism to evolve in a particular way. Of course, in the decades of genetic algorithms, no one has ever found such code. Indeed, that’s a huge black mark against the possible existence of a designer. No one has ever found anything in any organism’s genome that would indicate this ‘front-loading’ of genetic plans such that it would be easy to evolve a new function.
Nope, organisms, digital or organic, have to evolve the hard way. The researchers show this by running the simulation over 100 times. The ‘climber’ strategy only appears in about 12% of the 100 simulations. Since it appears to be an extremely effective tactic, one would think that a front-loaded genome would produce climbers more often than anything else, since it’s the best strategy.
This is just another of the things that creationists don’t understand about evolution. Evolution doesn’t result in the best organism, just one that is good enough given the previous generation and a few mutations.
As far as the other comment in that thread, “can mutations generate macroevolution”… well, that’s another creationist misunderstanding. It’s all just evolution. I’ve talked about it before.
But that’s the whole creationist schtick of people like Meyer. Misrepresent the actual evidence, takes quotes out of context, and when shown that one is wrong, move the goal posts. It’s so common that I’m not even sure that the followers of the ID movement realize that they are doing it.